So far the water and gas utilility companies have carried out the consumption reading of such services at the user's place, so they later can bill the corresponding service used by the consumer. However, new technological systems have been proposed lately, such as a prepayment supplying system for electricity, water or gas, as a way to overcome some of the disadvantages traditional billing systems have.
A kind of prepayment system was designed in order to purchase the electricity, water or gas supply directly from the central station. The information about the amount purchased is then transferred to a measuring device installed at the client's place (for instance, his store, establishment, office, home, etc.), where the service is used. The system receives the information about the prepayment and transfers the amount acquired at the central station. The measuring device usually consists of a mechanical meter located outside the client's place. It generally includes an interface or terminal placed adjacent to the meter, it reads the prepayment information or, alternatively, such interface is connected by means of a cable, or by means of the same cables of the water or gas supplying system, to the meter in case the latter is located inside the client's place. A disadvantage these prepayment systems have is that they need specific devices which are expensive and difficult to install. Another problem is their lack of capability to send back to the central station the information about the consumption, the way the credit is used, which meter is using such credit, as well as information concerning unlawful use of the meter. This kind of systems is known as unidirectional communication system.
Another kind of prepayment system known is also based on purchasing the water or gas service directly from the central station or other previously assigned stations. The information about the amount purchased is stored in a magnetic stripe card or in contact smart cards (hereafter called “contact card”). This particular prepayment system needs, by all means, the mechanical gas or water meter to have an external card reader or a magnetic key and a series of additional control devices that monitor the m3 of water or gas supply. The card reader device has a slot into which the contact card is inserted in order to transfer the information of the prepayment service. Examples of this system are disclosed in FR 2 777 677, EP 0 863 492, CN 1952613, 1952617, CN 2257636, CN 2444211 CN 2565000, CN 2727862, CN 2784887, CN 2837796, and WO 99/42963.
Nonetheless, there is a large disadvantage in this kind of prepayment card reader meters. The reader device must be accessible from the outside in order for the prepayment cards to be inserted. This makes it vulnerable to damage (voluntary or involuntary) by the user, by saline environment or by relatively high humidity. When the contact card is frequently used, its magnetic stripe or its chip may wear out causing the card and the transfer of information difficult to be read. Another problem occurs when the contact card reader is connected to the meter by means of a cable, due to such cable is also exposed to damage. There have been attempts to integrate the reader into the meter. The problem is that the meter has to undergo important design changes which apart from increasing its size, they make it more vulnerable to damage by being partly exposed to the environment and by making it incompatible with the connectors existing in the market nowadays.
Other kind of prepayment systems that control the water and gas supply are the ones that include some devices that cut off the supply by being automatically activated when the credit has run out.
Most of the water or gas meters used in the prepayment systems include mechanical elements that register the consumption of such services. This kind of meters use a mechanical register composed of a gear train that measures the m3, liters and tenths of liters of water or gas. The disadvantage with this kind of meters is that they are exposed to unlawful acts due to the fact that they can register the circulating flow in one way. However, if the meter registering mechanism is inverted, it will start to circulate backwards to register a decrease in the consumption in terms of the last reading.
Another fault in the prepayment meters previously described, particularly in water meters, lies in the fact that the mechanical elements that register the water service do not stand the water hammer produced by the high pressure generated when the water supply is provided in a controlled and scheduled way. The water hammer ends up damaging such mechanical elements. There is yet another disadvantage in this kind of meter under the circumstances of controlled and scheduled water supply, the mechanical elements that register the consumption will be activated by the air trapped and led through the pipes starting to deduct the water consumption from the prepaid amount at the moment the air circulates through such meter elements.
Having the above-mentioned faults into account, the object of this invention is to provide a prepayment system that controls more efficiently the water or gas supply by means of a meter installed in the client's place based on the prepaid service amount.
Another object of the present invention is to provide a prepayment measuring system concerning the prepaid water or gas consumption in m3 using a hermetically closed integrated meter along with a wireless intelligent card. Another object of the present invention is to provide a prepayment water or gas consumption measuring system that integrates an automatic device to interrupt the water or gas supply.
Another object of the present invention is to provide a prepayment system for measuring the prepaid water or gas consumption in m3 and which by means of a wireless intelligent card provides the supplier of the service with information about the consumption, about how the credit is used, where or which meter is using the credit and also information about unlawful acts and manipulation done to the meter.
One more object of the present invention is to provide a prepayment method for the m3 water or gas supply by means of a system consisting of a wireless card-reader.
Another object of the present invention is to provide a meter that includes electronic means that register the consumption in a bidirectional system regardless of how the meter is connected.
Another object of the present invention is to provide a prepayment system and a meter including means that detect and release the air trapped in the pipes and the air that circulates through the meter. Such means release the air that circulates in the water pipes and the one that reaches the meter, preventing this air from being registered as water flow that does not circulate in the meter.